Supporting device for display units

ABSTRACT

A supporting device for display units enables height adjustment with ease and accuracy, and stably maintains the adjusted height while allowing a plurality of display units to be mounted thereon. The supporting device includes a stationary member, an elevation member coupled to the stationary member so as to be raised or lowered, a rack gear secured to the stationary member, a pinion gear installed to the elevation member so as to engage with the rack gear, and a restriction unit installed to the elevation member to restrict or allow rotation of the pinion gear. The supporting device further comprises an upper-side supporting member installed to an upper portion of the elevation member, first and second movable members to move along a guide rail of the upper-side supporting member, and connecting devices installed to the respective movable members to connect the display unit, respectively.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.A. §119 of Korean PatentApplication No. 2006-0021012, filed on Mar. 6, 2006 in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a supporting device for display units,and, more particularly, to a supporting device for display units, whichcan adjust a height of the display unit with accuracy, maintain theadjusted height thereof with stability, and allows display units havingdifferent weights to be selectively mounted thereon.

2. Description of the Related Art

Generally, a display unit such as a liquid crystal display and a plasmadisplay panel is supported by a supporting device, which can stablysupport the panel, and allow adjustment in height of the panel. Oneexample of such a supporting device is disclosed in Korean Utility ModelRegistration No. 20-361843.

The supporting device disclosed in the publication comprises a standbody secured in a state of standing upright to a stand base, and anelevation support body coupled to the stand body so as to be raised orlowered with a display unit mounted thereon. The elevation support bodyis supported by a spiral spring, which is installed to the stand body toprovide lifting force acting against the weight of the display unit. Thespiral spring is set to have elasticity (restoring force) balanced withthe weight of the display unit. Accordingly, the supporting device isdesigned to allow the elevation support body to be stopped at a locationto which the display unit is lowered and at a location to which thedisplay unit is lifted.

However, since the elasticity of the spiral spring of the supportingdevice is predetermined, there is a problem in that, if other displayunits having different weights from that of a standard display unit aremounted on the supporting device, equilibrium between the elasticity ofthe spiral spring and the weight of the display unit is disrupted,causing the supporting device not to exhibit the height adjustmentfunction. In other words, if a display unit heavier than the standarddisplay unit is mounted on the supporting device, the elevation supportbody is lowered, whereas if a display unit lighter than the standarddisplay unit is mounted thereon, the elevation support body is lifted,so that the supporting device fails to exhibit the height adjustmentfunction. As a result, the supporting device cannot be commonly used forthe display units having different weights.

Korean Patent Laid-open Publication No. 2005-0066256 discloses a heightadjustable stand for a display unit, which can adjust the height of thedisplay unit, and then maintain the adjusted height thereof. However,such a supporting device has a problem in that, since fixing grooves areseparated a great distance from each other on a side surface of a fixingpart, and since height adjustment positions are restricted to locationsof the fixing grooves, adjustment in height of the display unit cannotbe performed with accuracy.

Korean Utility Model Registration No. 20-388004 discloses a stand fordisplay units, which enables a plurality of display units to besimultaneously mounted in a limited space. However, since it isnecessary, for use of the stand, to fasten or release fastening screwsor nuts whenever installation angles of the display units or separationdistances therebetween are adjusted, the stand has a difficulty inadjustment of the installation angles and the separation distancestherebetween. Accordingly, it is inconvenient to use such a stand insuch a case where the adjustment in distance between the display unitsis frequently required.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide asupporting device for display units, which enables adjustment in heightof a display unit with ease and accuracy, and stably maintains theadjusted height of the display unit while allowing display units havingdifferent weight to be selectively mounted thereon.

It is another aspect of the present invention to provide the supportingdevice, which allows a plurality of display units to be used in amounted state thereon, and enables easy adjustment of distance andinstallation angle between the display units.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be apparentfrom the description, or may be learned by practice of the invention.

The foregoing and other aspects of the present invention are achieved byproviding a supporting device for display units, comprising a stationarymember secured to a base, and an elevation member coupled to thestationary member so as to be raised or lowered to support the displayunit and adjust a height thereof, the supporting device furthercomprising: a rack gear secured to the stationary member; a pinion geardisposed on the elevation member so as to engage with the rack gear; anda restriction unit disposed on the elevation member to restrict or allowrotation of the pinion gear.

The restriction unit may comprise a lever coupled to the elevationmember and having a gear part to restrict the pinion gear, an operatingpart positioned opposite to the gear part of the lever, and an elasticmember to press the lever to cause the gear part of the lever to operatein a direction of restricting the pinion gear.

The lever may be installed such that, when pressing the operating part,the gear part is separated from the pinion gear.

The supporting device may further comprise a lift spring installedbetween the stationary member and the elevation member to impart liftingforce to the elevation member.

The lift spring may comprise a spiral spring having one end secured tothe stationary member, and the elevation member may be provided with aspring latching member to allow the spiral spring to be wound or unwoundaccording to a lifting or lowering behavior of the elevation member.

The supporting device may further comprise: an upper-side supportingmember mounted to an upper portion of the elevation member and extendingin a horizontal direction; a guide rail extending in a longitudinaldirection on the upper-side supporting member; first and second movablemembers positioned at both sides of the upper-side supporting member tomove along the guide rail, respectively; and connecting devices, eachhaving a hinging part and a rotating part to adjust an installationangle of the display unit, installed to the first and second movablemembers, respectively.

Each of the connecting devices may comprise a first connecting memberconnected with an associated one of the first and second movable membersso as to be hinged left and right to obtain a swivel function, a secondconnecting member connected with the first connecting member so as to behinged up and down to obtain a tilting function, and a third connectingmember rotatably connected with the second connecting member to obtain apivot function.

In accordance with another aspect of the present invention, a supportingdevice for display units is provided, comprising a stationary membersecured to a base, and an elevation member coupled to the stationarymember so as to be raised or lowered to support the display unit andadjust a height thereof, wherein the supporting device furthercomprises: a rack gear secured to the elevation member; a pinion geardisposed on the stationary member so as to engage with the rack gear;and a restriction unit disposed on the stationary member to restrict orallow rotation of the pinion gear.

The restriction unit may comprise: a lever coupled to the stationarymember and having a gear part to restrict the pinion gear; an operatingpart positioned opposite to the gear part of the lever; and an elasticmember to press the lever to cause the gear part of the lever to operatein a direction of restricting the pinion gear.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe exemplary embodiments, taken in conjunction with the accompanyingdrawings, of which:

FIG. 1 is a perspective view illustrating the construction of asupporting device for display units in accordance with one embodiment ofthe present invention;

FIG. 2 is an exploded perspective view illustrating one embodiment of aheight adjustor of the supporting device in accordance with the presentinvention;

FIG. 3 is a cross-sectional view illustrating the height adjustor of thesupporting device, in which an elevation member is in a secured state;

FIG. 4 is a cross-sectional view illustrating the height adjustor of thesupporting device in which the elevation member is in a lifting state;

FIG. 5 is a cross-sectional view illustrating another embodiment of aheight adjustor of the supporting device for the display unit inaccordance with the present invention;

FIG. 6 is an exploded perspective view illustrating details of anupper-side supporting member and a connecting device of the supportingdevice;

FIGS. 7 and 8 are views illustrating using states of the supportingdevice for the display unit via a pivot function and a distanceadjustment function thereof; and

FIG. 9 is a perspective view illustrating a supporting device fordisplay units in accordance with another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference will now be made in detail to the exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout the drawings. The embodiments are described below to explainthe present invention by referring to the figures.

Referring to FIG. 1, a supporting device for display units according tothe present invention comprises a stationary member 10 secured to a base1, and an elevation member 20 coupled to the stationary member 10 so asto be lifted or lowered for height adjustment. In addition, thesupporting device comprises an upper-side supporting member 60 installedto an upper side of the elevation member 20 to mount a plurality ofdisplay units, first and second movable members 71 and 72 installed atboth sides of the upper-side supporting member 60 so as to move in atransverse direction, and connecting devices 80 installed to therespective movable members 71 and 72 to connect the display units.

As shown in FIGS. 1 and 2, the stationary member 10 stands upright, andhas a lower end secured to an upper surface of the base 1 via alower-side connecting member 2. The lower-side connecting member 2 isfastened to the base 1 and the stationary member 10 via fasteningscrews. Herein, although the stationary member 10 is illustrated asbeing secured to the base 1 through the lower-side connecting member 2,the stationary member 10 can be secured directly to the base 1 viafastening screws or welding.

As shown in FIG. 2, the stationary member 10 extends in the verticaldirection, and is provided at either side with a first rail 11 whichguides lifting or lowering of the elevation member 20 after beingcoupled to the elevation member 20. The elevation member 20 also extendsin the vertical direction like the stationary member 10, and is providedat either side with a second rail 21 which is correspondingly coupled tothe first rail 11 of the stationary member 10. The first and secondrails 11 and 21 can be coupled to each other so as to slide with respectto each other. In this regard, although not shown in the drawings, thefirst and second rails 11 and 21 are coupled to each other via aplurality of balls or rollers in order to ensure a smooth lifting andlowering behavior of the elevation member 20.

A lift spring 30 is installed in a space between the stationary member10 and the elevation member 20 to impart lifting force to the elevationmember 20, as shown in FIGS. 2 and 3. The lift spring 30 comprises aspiral spring which is secured at its one end to an inner surface of thestationary member 10 and has elasticity to wind upwardly. The elevationmember 20 is provided with a spring latching member 31 which is latchedto a winding portion of the lift spring 30 such that the lift spring 30is wound or unwound according to the lifting or lowering behavior of theelevation member 20. Accordingly, the lift spring 30 tends to push thespring latching member 31 upward, thereby imparting the lifting force tothe elevation member 20. Here, although the spiral spring is provided asone example of the lift spring 30, it should be noted that the liftspring 30 is not limited to this construction. As for the lift spring, atension coil spring or a compression coil spring which can impart thelifting force to the elevation member 20 may be employed.

The elasticity (restoring force) of the lift spring 30 imparts thelifting force to the elevation member 20 so that, even when a load of adisplay unit is applied to the elevation member 20, the height of thedisplay unit can be easily adjusted by a user. Accordingly, it isdesirable to set the elasticity of the lift spring 30 such that alowering force of the elevation member 20 caused by the weight of thedisplay unit is balanced with the elasticity of the lift spring 30.

A height adjustor 40 is positioned in an upper space between thestationary member 10 and the elevation member 20 to adjust the height ofthe elevation member 20. As shown in FIGS. 2 and 3, the height adjustor40 comprises a rack gear 41 secured to the inner surface of thestationary member 10 and extending in the vertical direction, a piniongear 42 installed to the elevation member 20 so as to engage with therack gear 41, a restriction unit 50 installed to the elevation member 20to restrict or allow rotation of the pinion gear 42, and a supportbracket 43 secured to the inner surface of the elevation member 20 forinstallation of the pinion gear 42 and the restriction unit 50.

The support bracket 43 is secured to the inner surface of the elevationmember 20 via welding, fastening screws, and the like. The pinion gear42 is rotatably coupled to a lower end of the support bracket 43 via acoupling pin 44 such that teeth of the pinion gear 42 engage with therack gear 41. Accordingly, the pinion gear 42 moves and rotates up ordown along the rack gear 41 when the elevation member 20 is lifted orlowered.

The restriction unit 50 serves to restrict the pinion gear 42, andcomprises a lever 51, which is coupled at the center to the supportbracket 43 via a coupling pin 53 so as to move like a seesaw and has agear part 52 to engage with the pinion gear 42, an operating part 54positioned opposite to the gear part 52 of the lever 51, and an elasticmember 55 to press the operating part 54 of the lever 51 to cause thegear part 52 of lever 51 to operate in a direction of restricting thepinion gear 42. As shown in FIG. 3, the operating part 54 is protrudedoutwardly at the rear side of the elevation member 20 through a hole 23formed in the elevation member 20. The elastic member 55 forces the endof the lever 51 at a side of the operating part 54 within the supportbracket 43 to be protruded to the outside. It should be noted that,without being limited to this construction, the elastic member 55 may berealized by a torsion spring installed at a portion to which thecoupling pin 53 of the lever 51 is mounted.

When the operating part 54 is pushed by the user, the gear part 52 isseparated from the pinion gear 42, the restriction unit 50 releases thepinion gear 42, as shown in FIG. 4. In addition, when the operating part54 is released by the user, the lever 51 is rotated by the elasticity ofthe elastic member 55, causing the gear part 52 to engage and restrictthe pinion gear 42.

Accordingly, if the user wants to move the elevation member 20 up ordown for the height adjustment of the display unit, the elevation member20 is lifted or lowered, with the restriction of the gear part 52 on thepinion gear 42 released by pushing the operating part 54. Then, if theuser wants to fix the height of the elevation member 20 after suitablyadjusting the height of the display unit, the operating part 54 isreleased to force the gear part 52 to restrict the pinion gear 42. Whenthe pinion gear 42 is restricted, rotation of the pinion gear 42 isrestricted, and prevents the elevation member 20 from being lifted.Thus, it is possible to maintain a fixed state of the elevation member20 with stability after the height adjustment.

Since the height adjustor 40 has the structure wherein the pinion gear42 moves and rotates along the rack gear 41 during the height adjustmentof the elevation member 20, the height adjustment of the elevationmember 20 can be easily performed. Furthermore, since it is possible torestrict the pinion gear 42 at any desired position when fixing theelevation member 20 after the height adjustment, the height of theelevation member 20 can be accurately adjusted. In particular, moreaccurate height adjustment can be realized by decreasing a pitch of therack gear 41, the pinion gear 42, and the gear part of the lever 52.

In addition, since the supporting device for the display unit consistentwith the present invention can secure the elevation member 20 by meansof the restriction unit 50 after the height adjustment, it is possibleto maintain the adjusted height with stability even in the case where adisplay unit heavier or lighter than the standard display unit ismounted on the supporting device according to needs of the user. Inother words, in the case where a display unit that is heavier than thestandard display unit is mounted on the supporting device, the load ofthe display unit applied to the elevation member 20 is greater than theelasticity of the lift spring 30, causing the elevation member 20 to belowered. However, even in this case, since the elevation member 20 isforcibly restricted by means of the restriction unit 50, it is possibleto stably maintain the adjusted height of the elevation member 20.Likewise, in the case where the display unit lighter than the standarddisplay unit is mounted on the supporting device, since the elevationmember 20 can be restricted, it is possible to stably maintain theadjusted height of the elevation member 20.

Accordingly, since the supporting device of the present invention canadjust the height of the elevation member 20 irrespective of the loadapplied to the elevation member 20; that is, the number or the weightsof the display units directly or indirectly mounted on the elevationmember 20, and can maintain the adjusted height of the elevation member20 via restriction of the pinion gear 42 after the height adjustment, itcan be commonly used to support various display units.

FIG. 1 shows one embodiment of the supporting device for the displayunit, which has the upper-side supporting member 60 installed at theupper end of the elevation member 20, and allows the plurality ofdisplay units to be mounted on the upper-side supporting member 60.However, the present invention is not limited to this construction, andcan be applied to the case where a single display unit is mounted on theupper portion of the elevation member 20 as shown in FIG. 9. In FIG. 9,the supporting device comprises an upper-side supporting member 600positioned at an upper end of the elevation member 20, and a singleconnecting device 800 which mounts the single display unit to theupper-side supporting member 600.

FIG. 5 is a cross-sectional view illustrating another embodiment of aheight adjustor 400 of the supporting device for the display unitconsistent with the present invention. Unlike height adjustor shown inFIG. 1, in the height adjustor 400 of the embodiment shown in FIG. 5, arack gear 410 is installed to the elevation member 20, and a pinion gear420, a restriction unit 500 and a support bracket 430 are installed tothe stationary member 10. The pinion gear 420 is rotatably coupled to anupper portion of the support bracket 430 so as to engage with the rackgear 410, and is installed such that a gear part 520 of a lever 510rotatably coupled to the support bracket 430 engages with the piniongear 420. An operating part 540 of the lever 510 is protruded at thefront of the stationary member 10 through a hole 13 formed in thestationary member 10, and an elastic member 550 supports the end of thelever 510 at a side of the operating part 540. In this embodiment, therack gear 410 is lifted via a lifting behavior of the elevation member20, causing the pinion gear 420 mounted to the stationary member 10 torotate without being lifted or lowered. The pinion gear 420 isrestricted or released according to operation of the restriction unit500. Accordingly, the height adjustor 400 of this embodiment operateswith the substantially same function as that of the height adjustor 40described above.

As shown in FIGS. 1 and 6, in both embodiments, the upper-sidesupporting member 60 is mounted on the upper portion of the elevationmember 20. The upper-side supporting member 60 extends in the horizontaldirection, and has a middle portion secured to the upper end of theelevation member 20 via a connecting member 61. Although the upper-sidesupporting member 60 is described as being secured by the upper-sideconnecting member 61 in the embodiment of FIG. 1, the upper-sidesupporting member 60 can be directly coupled to the upper end of theelevation member 20.

As shown in FIG. 1, the upper-side supporting member 60 is provided witha guide rail 62, which extends in the longitudinal direction and hasfirst and second movable members 71 and 72 installed at both sides ofthe guide rail 62 so as to move in the horizontal direction with thedisplay units mounted thereon. The first and second movable members 71and 72 are slidably coupled to the guide rail 62 so as to move in thehorizontal direction. The first and second movable members 71 and 72 areprovided with connecting devices 80 which connect the display unitsthereto, respectively.

As shown in FIG. 6, each of the connecting devices 80 is constructed tobe hinged and rotated in order to adjust installation angle anddirection of the display unit according to the needs of the user. Tothis end, the connecting device 80 comprises a first connecting member81 connected with an associated one of the first and second movablemembers 71 and 72 via a first connecting pin 84 so as to be hinged leftand right, a second connecting member 82 connected with the firstconnecting member 81 via a second connecting pin 85 so as to be hingedup and down, and a third connecting member 83 rotatably connected at itscenter with the second connecting member 82. In order to prevent aportion coupled to the second connecting pin 85 from being elongated dueto the weight of the display unit, a torsion spring 86 is provided tothis portion, and supports the second connection member 82 to rotate itupwardly.

With this structure, the connecting devices 80 can realize a swivelfunction to adjust the left and right installation angles of a displayscreen, a tilt function to adjust a slant of the display screen, and apivot function to pivot the display screen.

The pivot function to pivot display units M1 and M2 can be realized asshown in FIGS. 7 and 8. Specifically, the connecting devices 80 can beused to allow screens of the display units M1 and M2 to be laidhorizontally, as shown in FIG. 7, or to be stood vertically, as shown inFIG. 8. When using the display units after changing directions of thescreens as described above, it is necessary to adjust a distance betweenthe display units M1 and M2. The distance between the display units M1and M2 can be adjusted by moving the display units M1 and M2 in thehorizontal direction. According to the present invention, since thefirst and second movable members 71 and 72 can be moved in thehorizontal direction along the guide rail 62 of the upper-sidesupporting member 60, the distance between the display units M1 and M2can be easily adjusted.

As apparent from the above description, consistent with the presentinvention, height adjustment of the display unit can be performed withease and accuracy through the structure of the supporting device whereina pinion gear moves and rotates along a rack gear to lift or lower anelevation member, and the structure wherein the pinion gear can beeasily restricted at any desired position to maintain the adjustedheight of the elevation member.

In addition, consistent with the present invention, when mounting adisplay unit that is heavier or lighter than the standard display uniton the supporting device according to the needs of the user, theadjusted height can be maintained with stability through the structurewherein the pinion gear is restricted by means of a restriction unitafter adjusting the height of the elevation member.

In addition, consistent with the present invention, a plurality ofdisplay units can be mounted on the supporting device by means of theupper-side supporting member, and can be easily adjusted in distancetherebetween, if necessary, through the structure wherein first andsecond movable members can be moved in the horizontal direction alongthe guide rail.

Furthermore, consistent with the present invention, installation anglesand directions of the display units can be freely adjusted by means ofthe connecting devices which are mounted to the movable members toconnect the display units, and have the swivel function, tilt functionand pivot function.

Although a few exemplary embodiments of the present invention have beenshown and described, it would be appreciated by those skilled in the artthat various modifications, additions and substitutions may be made inthese embodiments without departing from the principle and spirit of theinvention, the scope of which is defined in the claims and theirequivalents.

1. A supporting device for display units, comprising a stationary membersecured to a base, and an elevation member coupled to the stationarymember so as to be raised or lowered to support the display unit andadjust a height thereof, the supporting device further comprising: arack gear secured to the stationary member; a pinion gear disposed onthe elevation member so as to engage with the rack gear; and arestriction unit disposed on the elevation member to restrict or allowrotation of the pinion gear.
 2. The supporting device according to claim1, wherein the restriction unit comprises a lever coupled to theelevation member and having a gear part to restrict the pinion gear, anoperating part positioned opposite to the gear part of the lever, and anelastic member to press the lever to cause the gear part of the lever tooperate in a direction of restricting the pinion gear.
 3. The supportingdevice according to claim 2, wherein the lever is installed such that,when pressing the operating part, the gear part is separated from thepinion gear.
 4. The supporting device according to claim 2, furthercomprising: a lift spring installed between the stationary member andthe elevation member to impart lifting force to the elevation member. 5.The supporting device according to claim 4, wherein the lift springcomprises a spiral spring having one end secured to the stationarymember, and the elevation member is provided with a spring latchingmember to allow the spiral spring to be wound or unwound according to alifting or lowering behavior of the elevation member.
 6. The supportingdevice according to claim 1, further comprising: an upper-sidesupporting member mounted to an upper portion of the elevation memberand extending in a horizontal direction; a guide rail extending in alongitudinal direction on the upper-side supporting member; first andsecond movable members positioned at both sides of the upper-sidesupporting member to move along the guide rail, respectively; andconnecting devices, each having a hinging part and a rotating part toadjust an installation angle of the display unit, installed to the firstand second movable members, respectively.
 7. The supporting deviceaccording to claim 5, wherein each of the connecting devices comprises afirst connecting member connected with an associated one of the firstand second movable members so as to be hinged left and right to obtain aswivel function, a second connecting member connected with the firstconnecting member so as to be hinged up and down to obtain a tiltingfunction, and a third connecting member rotatably connected with thesecond connecting member to obtain a pivot function.
 8. The supportingdevice according to claim 1, further comprising: an upper-sidesupporting member mounted to an upper portion of the elevation memberand extending in a horizontal direction; and a connecting device havinga hinging part and a rotating part to adjust an installation angle ofthe display unit installed to the upper-side supporting member.
 9. Asupporting device for display units, comprising a stationary membersecured to a base, and an elevation member coupled to the stationarymember so as to be raised or lowered to support the display unit andadjust a height thereof, the supporting device further comprising: arack gear secured to the elevation member; a pinion gear disposed on thestationary member so as to engage with the rack gear; and a restrictionunit disposed on the stationary member to restrict or allow rotation ofthe pinion gear.
 10. The supporting device according to claim 9, whereinthe restriction unit comprises a lever coupled to the stationary memberand having a gear part to restrict the pinion gear; an operating partpositioned opposite to the gear part of the lever; and an elastic memberto press the lever to cause the gear part of the lever to operate in adirection of restricting the pinion gear.
 11. The supporting deviceaccording to claim 10, wherein the lever is installed such that, whenpressing the operating part, the gear part is separated from the piniongear.
 12. The supporting device according to claim 10, furthercomprising: a lift spring installed between the stationary member andthe elevation member to impart lifting force to the elevation member.13. The supporting device according to claim 9, further comprising: anupper-side supporting member mounted to an upper portion of theelevation member and extending in a horizontal direction; a guide railextending in a longitudinal direction on the upper-side supportingmember; first and second movable members positioned at both sides of theupper-side supporting member to move along the guide rail, respectively;and connecting devices, each having a hinging part and a rotating partto adjust an installation angle of the display unit, installed to thefirst and second movable members, respectively.
 14. The supportingdevice according to claim 9, further comprising: an upper-sidesupporting member mounted to an upper portion of the elevation memberand extending in a horizontal direction; and a connecting device havinga hinging part and a rotating part to adjust an installation angle ofthe display unit installed to the upper-side supporting member.